WO2021054113A1

WO2021054113A1 - Method for manufacturing fuel battery cell separator gasket

Info

Publication number: WO2021054113A1
Application number: PCT/JP2020/033026
Authority: WO
Inventors: 泰輔松田; 茂渡部
Original assignee: Nok株式会社
Priority date: 2019-09-18
Filing date: 2020-09-01
Publication date: 2021-03-25
Also published as: EP4033574A1; US11973246B2; EP4033574A4; CN113767490A; JPWO2021054113A1; JP7385668B2; US20220302475A1

Abstract

A fuel battery separator gasket 203 is formed via a shaping step for an adhesive 211 and a transfer step for the adhesive 211. During the shaping step, a shaping mold is used to shape the adhesive 211, which will become the gasket 203, on a flexible substrate 301 having flexibility. During the transfer step, the adhesive 211 shaped on the flexible substrate 301 is transferred to one (for example, the separator 11B) from among a pair of separators 11 that face each other with an electrolyte film, which is provided to the fuel cell, interposed therebetween and that have a bead 14 which is close to the electrolyte film and which forms a fluid flow path between the bead and the electrolyte film, thereby forming the gasket 203. Through this method, it is possible to shape a gasket on a separator without causing destruction or damage.

Description

Gasket manufacturing method for fuel cell separator

Regarding the method of manufacturing gaskets for fuel cell separators.

Fuel cells that generate electricity by electrochemically reacting reaction gas are rapidly becoming widespread. Fuel cells are attracting attention as a preferable energy source because they have high power generation efficiency and have little impact on the environment.

Among the fuel cells, the polymer electrolyte type has a stack structure in which a plurality of fuel cell cells are stacked. Each fuel cell has a membrane electrode assembly (MEA) sandwiched between a pair of separators. The membrane electrode joint is a structure in which an electrolyte membrane is sandwiched between an anode electrode (anode) and a cathode electrode (cathode), and each electrode has a laminated structure of a catalyst layer and a gas diffusion layer (GDL). ing. The separator is in close contact with the gas diffusion layer and forms a flow path for hydrogen and oxygen with the gas diffusion layer.

Such a fuel cell uses a flow path formed in a separator to supply hydrogen to the anode electrode and oxygen to the cathode electrode. As a result, power is generated by the electrochemical reaction opposite to the electrolysis of water.

As shown in each figure of Patent Document 1, the electrolyte membrane (reference numeral 55 in Document 1) of the membrane electrode assembly is sealed at the end. As the seal, for example, gaskets (gaskets main bodies 21 and 31) formed of a rubber-like elastic body as described in Patent Document 1 are used. The gasket elastically deforms in a direction orthogonal to the surface of the separator and seals the electrolyte membrane of the membrane electrode assembly between the pair of separators.

Japanese Unexamined Patent Publication No. 2016-143479

The gasket that seals the electrolyte membrane is formed on the separator by injection molding or transfer molding. At this time, a brittle separator such as one made of carbon may be destroyed by the pressure at the time of gasket molding, for example, the pressure due to the mold press or the injection pressure. Further, even with a relatively hard metal separator, if a carbon coating or the like is applied to the surface, the coating may be damaged by the pressure during gasket molding.

It is required to be able to mold the gasket on the separator without causing breakage or damage.

One aspect of the method for manufacturing a gasket for a fuel cell separator is to form an adhesive to be a gasket on a flexible base material using a molding mold, face the mating member with the mating member in between, and bring the mating member into close contact with the mating member. The gasket is formed by transferring the pressure-sensitive adhesive formed on the flexible base material to one of a pair of separators having beads that form a fluid flow path with the mating member of the lever.

Another aspect of the method for manufacturing a gasket for a fuel cell separator is to use a molding mold to shape an adhesive to be a gasket on an intermediate base material, and apply the adhesive to the intermediate base material with respect to a flexible base material having flexibility. The formed adhesive is transferred to one of a pair of separators having a bead that faces the mating member with the mating member in between and has a bead that is in close contact with the mating member to form a fluid flow path with the mating member. On the other hand, the pressure-sensitive adhesive transferred to the flexible base material is transferred to form the gasket.

In yet another aspect of the method for manufacturing a gasket for a fuel cell separator, an adhesive serving as a gasket is formed on the lower mold of a molding mold having an upper mold and a lower mold, and the mating member is sandwiched between them to face each other. The gasket is transferred from the adhesive formed on the lower mold to one of a pair of separators having a bead that is in close contact with the mating member and forms a fluid flow path between the mating member and the mating member. To mold.

A gasket can be molded on the separator without causing breakage or damage.

The schematic diagram which conceptually shows the stack structure in which a plurality of fuel cell cells are laminated. (A) to (C) are vertical cross-sectional views showing over time each step executed at the time of shaping the pressure-sensitive adhesive as the first embodiment. (A) to (D) are vertical cross-sectional views showing over time each step performed when transferring the pressure-sensitive adhesive to the separator as the first embodiment. A vertical sectional view showing a sealing structure for sealing a gap between a pair of separators. (A) to (C) are vertical cross-sectional views showing with time each step executed at the time of shaping the pressure-sensitive adhesive as the second embodiment. (A) to (D) are vertical cross-sectional views showing over time each step performed when transferring the pressure-sensitive adhesive to the separator as the second embodiment. (A) to (D) are vertical cross-sectional views showing with time each step executed at the time of shaping the pressure-sensitive adhesive as the third embodiment. (A) to (E) are vertical cross-sectional views showing over time each step performed when transferring the pressure-sensitive adhesive to the separator as the third embodiment. (A) to (C) are vertical cross-sectional views showing over time each step executed at the time of shaping the pressure-sensitive adhesive as the fourth embodiment. (A) to (C) are vertical cross-sectional views showing over time each step performed in the first stage transfer of the pressure-sensitive adhesive to the separator as the fourth embodiment. (A) to (C) are vertical cross-sectional views showing over time each step performed in the second step transfer of the pressure-sensitive adhesive to the separator as the fourth embodiment. (A) to (C) are vertical cross-sectional views showing over time each step executed at the time of shaping the pressure-sensitive adhesive as the fifth embodiment. (A) to (D) are vertical cross-sectional views showing over time each step performed when transferring the pressure-sensitive adhesive to the separator as the fifth embodiment. (A) to (C) are vertical cross-sectional views showing over time each step executed at the time of shaping the pressure-sensitive adhesive as the sixth embodiment. (A) to (D) are vertical cross-sectional views showing over time each step performed when transferring the pressure-sensitive adhesive to the separator as the sixth embodiment.

[Fuel cell]
The method for manufacturing a gasket for a fuel cell separator according to the present embodiment is an example of a method in which a gasket to be provided on a separator used in a fuel cell is shaped and the gasket is transferred to the separator. An example of a fuel cell to which the method of this embodiment is applied will be described first.

As shown in FIG. 1, the fuel cell 1 has a laminated structure in which a plurality of fuel cell cells 2 are laminated. In the fuel cell 2, an electrolyte membrane 102 provided with a membrane electrode assembly 101 called MEA (Membrane Electrode Assembly) is interposed between a pair of separators 11 for a fuel cell. Such fuel cell cells 2 are stacked via the cooling surface seal 201. In FIG. 1, only two sets of fuel cell 2 are drawn, but in reality, hundreds of sets of fuel cell cells 2 are stacked to form the fuel cell 1.

The membrane electrode assembly 101 is a structure in which electrodes (not shown) are provided at the central portions of both sides of the electrolyte membrane 102. The electrode has a laminated structure having a catalyst layer formed on the electrolyte film 102 and a gas diffusion layer (GDL) formed on the catalyst layer (neither is shown). In such an electrode, one side of the electrolyte membrane 102 is used as an anode electrode (anode), and the opposite side thereof is used as a cathode electrode (cathode).

The separator 11 for a fuel cell is, for example, a flat plate-shaped member formed of a resin such as carbon. However, the separator 11 is not limited to a brittle material such as that made of carbon, and as another example, a flat plate-like member that can be press-processed, such as a thin stainless steel plate, may be used as the separator 11.

The separator 11 has a rectangular planar shape, and is provided with an arrangement region 12 for arranging the membrane electrode assembly 101. Three openings provided at positions on both ends outside the arrangement region 12 are manifolds 13 for circulating a fluid used for power generation or generated by power generation. The fluid flowing through the manifold 13 is a fuel gas (hydrogen), an oxidizing gas (oxygen), water generated by an electrochemical reaction during power generation, excess oxidizing gas, a refrigerant, or the like.

The position is aligned with the manifold 13 provided on the separator 11, and the manifold 103 is also provided on the electrolyte membrane 102. These manifolds 103 are three openings provided at positions on both ends away from the membrane electrode assembly 101.

The fuel cell 1 uses the

manifolds

13 and 103 to guide the fuel gas (hydrogen) between the separator 11A facing one surface of the electrolyte membrane 102 provided with the membrane electrode assembly 101, and the fuel cell 1 with one surface of the electrolyte membrane 102. Oxidizing gas (oxygen) is guided between the separator 11B facing the opposite surface. The cooling water used as the refrigerant is guided between the two sets of fuel cell 2 sealed by the cooling surface seal 201. At this time, the fuel gas, the oxidation gas, and the cooling water flow through the respective flow paths formed by the pair of separators 11 (11A, 11B) that assemble the fuel cell 2.

The pair of separators 11 face each other with the electrolyte membrane 102 as a mating member interposed therebetween to form a fuel cell 2. The separator 11 includes a bead 14 that is in close contact with the electrolyte membrane 102 and forms a fluid flow path between the separator and the electrolyte membrane 102. The space between the electrolyte membrane 102 and the bead 14A of the separator 11A forms a flow path for the fuel gas. The space between the electrolyte membrane 102 and the bead 14B of the separator 11B forms a flow path for the oxidizing gas. The space between the

beads

14A and 14B provided between the separator 11A of the set of fuel cell 2 and the separator 11B of the fuel cell 2 overlapping the separator 11A forms a flow path for the cooling water.

The fuel cell 2 has a seal structure on the outer peripheral edge of the separator 11 and the membrane electrode assembly 101 and on the peripheral edges of the

manifolds

13 and 103. The seal structure includes a cooling surface seal 201 interposed between the two sets of fuel cell cells 2 and a reaction surface seal 202 provided between the separator 11 and the membrane electrode assembly 101. In such a seal structure, the flow path of the fuel gas and the surplus fuel gas, the flow path of the water generated by the electrochemical reaction of the oxidation gas and power generation, and the flow path of the cooling water as the refrigerant are made independent of each other. , Prevents mixing of different types of fluids.

A gasket 203 fixed to the separator 11 is used for the cooling surface seal 201 and the reaction surface seal 202 having a sealing structure. Hereinafter, embodiments of a method for manufacturing a gasket for a fuel cell separator will be described.

[First Embodiment]
The first embodiment will be described with reference to FIGS. 2 (A) to 2 (C) and FIGS. 3 (A) to 3 (D). The gasket manufacturing method of the present embodiment includes a shaping step and a transfer step.

(Shaping process)
The shaping step is a step of shaping a flexible base material 301 having flexibility, for example, a pressure-sensitive adhesive 211 to be a gasket 203 on a resin film.

As shown in FIG. 2A, the flexible base material 301 is placed on the base 401, and the molding die 411 is placed via the flexible base material 301. The molding die 411 is provided with a gate 412 and a cavity 413. The cavity 413 has a shape for forming the gasket 203.

As shown in FIG. 2B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413. As the molding method at this time, injection molding or transfer molding is adopted.

As shown in FIG. 2C, the pressure-sensitive adhesive 211 is formed on the flat surface of the flexible base material 301 by separating the molding die 411 from the base 401. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

In order to allow the adhesive 211 to be formed on the flexible base material 301 by separating the molding 411 from the base 401, the flexible base material 301 exhibits stronger adhesiveness than the wall portion of the cavity 413. Has been done.

As the pressure-sensitive adhesive 211 used in the shape step, for example, a rubber-based pressure-sensitive adhesive using butyl rubber, polyisobutylene rubber, styrene-butadiene rubber, ethylene-propylene diene rubber, natural rubber, or the like as a base polymer can be used.

It is also possible to add an additive to the adhesive 211. Additives that can be blended include, for example, cross-linking agents, tackifiers, fillers, anti-aging agents and the like.

(Transfer process)
The transfer step is a step of transferring the pressure-sensitive adhesive 211 formed on the flexible base material 301 to the separator 11 to form the gasket 203.

As shown in FIG. 3A, the pressure-sensitive adhesive 211 formed on the flexible base material 301 is faced with one of the separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. In the present embodiment, a region other than the bead 14B provided on the separator 11B is set as a fixed position.

As a modification of the present embodiment, the top of the bead 14B provided on the separator 11B may be set as a fixed position.

As shown in FIG. 3B, the separator 11B and the flexible base material 301 are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 3C, the flexible base material 301 is bent and peeled from the adhesive 211. At this time, the separator 11B is designed to exhibit stronger adhesiveness than the flexible base material 301. Therefore, the pressure-sensitive adhesive 211 maintains the state of being adhered to the flexible base material 301, and the flexible base material 301 is peeled off from the pressure-sensitive adhesive 211.

As shown in FIG. 3D, as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

The adhesive 211 serving as the gasket 203 may or may not be crosslinked. Cross-linking of the pressure-sensitive adhesive 211 is carried out after shaping on the flexible base material 301 or after transferring to the separator 11B.

In this way, the gasket 203 can be formed on the separator 11B. At this time, the separator 11B is not subjected to the pressure at the time of gasket molding, for example, the pressure due to the mold pressing or the injection pressure, and the gasket 203 can be molded on the separator 11B without causing breakage or damage. Therefore, as the separator 11 (11A, 11B), a brittle material such as one made of carbon can be used.

[Second Embodiment]
The second embodiment will be described with reference to FIGS. 4 to 6 (A) to 6 (D). The same parts as those in the first embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

FIG. 4 shows the seal structure of the cooling surface seal 201 and the reaction surface seal 202, which are the premise of the gasket manufacturing method of the present embodiment. In this seal structure, the beads 14 of the separator 11 are nested and overlapped with each other. As an example, the bead 14B of the separator 11B facing the surface opposite to one surface of the electrolyte membrane 102 is formed larger than the bead 14A of the separator 11A facing one surface of the electrolyte membrane 102 provided with the membrane electrode assembly 101. The bead 14B has entered the bead 14A in a non-contact state.

The beads 14 (14A, 14B) of the pair of separators 11 have a rising angle θ from the separator 11 of, for example, about 70 °. Therefore, the side walls 15 (15A, 15B) of the beads 14 (14A, 14B) facing each other of the pair of separators 11 are inclined with respect to the separator 11.

The gasket 203 used in such a sealing structure is arranged between the side walls 15 (15A, 15B) of the beads 14 (14A, 14B) facing each other by overlapping in a nested manner. At this time, since the rising angle θ of the bead 14 from the separator 11 is about 70 °, the gasket 203 has a parallelogram cross-sectional shape.

Similar to the first embodiment, since the gasket 203 is formed by the adhesive 211, it adheres to the side walls 15 (15A, 15B) of the beads 14 (14A, 14B) facing each other of the pair of separators 11. It is fixed. Further, the gasket 203 is adhered and fixed not only to the side wall 15 of the bead 14 but also to the surface of the separator 11 communicating with the side wall 15.

The gasket manufacturing method of the present embodiment produces a gasket 203 that conforms to the sealing structures of the cooling surface seal 201 and the reaction surface seal 202 as described above. The present manufacturing method includes a shaping step and a transfer step as in the first embodiment.

As shown in FIG. 5A, the flexible base material 301 is placed on the base 401, and the molding die 411 is placed via the flexible base material 301. The molding die 411 is provided with a gate 412 and a cavity 413.

The flexible base material 301 includes a protrusion 302 that enters between two adjacent beads 14B provided on one of the pair of separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). Like the bead 14B, the protrusion 302 rises from the flexible base material 301 at a rising angle of about 70 °. That is, the protrusion 302 is formed in a shape imitating the side wall 15B of the bead 14B to which the pressure-sensitive adhesive 211 serving as the gasket 203 adheres.

The cavity 413 provided in the molding die 411 has a shape for forming the gasket 203 at the portion where the protrusion 302 of the flexible base material 301 is arranged and in contact with the gate 412.

As shown in FIG. 5B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413. As the molding method at this time, injection molding or transfer molding is adopted.

As shown in FIG. 5C, by separating the molding die 411 from the base 401, the adhesive 211 is formed on the flexible base material 301 along the protrusion 302. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

As shown in FIG. 6A, the pressure-sensitive adhesive 211 formed on the flexible base material 301 is made to face the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. As shown in FIG. 4, the fixing position of the gasket 203 is the side wall 15B of the bead 14B which is nestedly overlapped with the bead 14A of the separator 11A on the side in contact with the fuel gas (hydrogen).

As shown in FIG. 6B, the separator 11B and the flexible base material 301 are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 6C, the flexible base material 301 is bent and peeled from the adhesive 211. At this time, the separator 11B is designed to exhibit stronger adhesiveness than the flexible base material 301. Therefore, the pressure-sensitive adhesive 211 keeps sticking to the separator 11B, and the flexible base material 301 is peeled off from the pressure-sensitive adhesive 211.

As shown in FIG. 6D, as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

[Third Embodiment]
The third embodiment will be described with reference to FIGS. 7 (A) to 7 (D) and FIGS. 8 (A) to 8 (E). The same parts as those of the second embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

This embodiment is an example in which the protrusion 302 is formed by embossing the material 212 of the pressure-sensitive adhesive 211 against the molding die 411 by embossing the material 212, instead of using the flexible base material 301 provided with the protrusion 302 in advance. .. In such a manufacturing method, a more flexible film-like flexible base material 301 is used as the flexible base material 301.

Similar to the method of the second embodiment, the gasket manufacturing method of the present embodiment also produces a gasket 203 that conforms to the seal structure of the cooling surface seal 201 and the reaction surface seal 202 as shown in FIG. The point that the shaping step and the transfer step are included is also the same as the gasket manufacturing method of the first and second embodiments.

(Shaping process)
The shaping step is a step of shaping the pressure-sensitive adhesive 211 to be the gasket 203 on the flexible base material 301 having flexibility such as a resin film. In this embodiment, the lower mold 411L and the upper mold 411U are used.

As shown in FIG. 7A, the flexible base material 301 is placed on the lower mold 411L, and the upper mold 411U is placed via the flexible base material 301. The lower mold 411L is provided with a protrusion 414, and the upper mold 411U is provided with a gate 412 and a cavity 413.

The protrusion 414 provided on the lower mold 411L corresponds to the protrusion 302 provided on the flexible base material 301 of the second embodiment, and is about 70 ° from the flexible base material 301 like the bead 14B. It stands up at the rising angle of. That is, the protrusion 302 is formed in a shape imitating the side wall 15B of the bead 14B to which the pressure-sensitive adhesive 211 serving as the gasket 203 adheres.

The cavity 413 provided in the upper mold 411U has a shape for arranging the protrusion 414 of the lower mold 411L and forming the gasket 203 in the portion communicating with the gate 412.

As shown in FIG. 7B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413.

As shown in FIG. 7C, the flexible base material 301 bends into the shape of the protrusion 414 due to the filling pressure of the material 212 of the adhesive 211 into the cavity 413.

As shown in FIG. 7D, by separating the upper mold 411U from the lower mold 411L, the adhesive 211 is formed on the flexible base material 301 along the protrusion 414. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

In order to allow the adhesive 211 to be formed on the flexible base material 301 by separating the upper mold 411U from the lower mold 411L, the flexible base material 301 exhibits stronger adhesiveness than the wall portion of the cavity 413. Has been made.

As shown in FIG. 8A, the adhesive 211 formed on the flexible base material 301 together with the lower mold 411L is made to face the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. As shown in FIG. 4, the fixing position of the gasket 203 is the side wall 15B of the bead 14B which is nestedly overlapped with the bead 14A of the separator 11A on the side in contact with the fuel gas (hydrogen).

As shown in FIG. 8B, the separator 11B attached to the lower mold 411L and the flexible base material 301 are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 8C, the lower mold 411L is removed from the flexible base material 301. At this time, the adhesive force between the flexible base material 301 and the lower mold 411L is greater than the adhesive force between the separator 11B and the pressure-sensitive adhesive 211 and the adhesive force between the pressure-sensitive adhesive 211 and the flexible base material 301. Due to its small size, the lower mold 411L can be smoothly removed from the flexible base material 301.

As shown in FIG. 8D, the flexible base material 301 is bent and peeled from the adhesive 211. At this time, the separator 11B is designed to exhibit stronger adhesiveness than the flexible base material 301. Therefore, the pressure-sensitive adhesive 211 maintains the state of being adhered to the flexible base material 301, and the flexible base material 301 is peeled off from the pressure-sensitive adhesive 211.

As shown in FIG. 8 (E), as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

[Fourth Embodiment]
A fourth embodiment will be described with reference to FIGS. 9 (A) to 9 (C) to 11 (A) to 11 (C). The same parts as those of the second embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the pressure-sensitive adhesive 211 is not directly shaped on the flexible base material 301, but is shaped on the intermediate base material 351 and transferred from the intermediate base material 351 to the flexible base material 301, and further formed on the flexible base material 301. Is transferred to the separator 11.

Similar to the method of the second embodiment, the gasket manufacturing method of the present embodiment also produces a gasket 203 that conforms to the seal structure of the cooling surface seal 201 and the reaction surface seal 202 as shown in FIG. The point that the shaping step and the transfer step are included is also the same as the gasket manufacturing method of the first and second embodiments. However, as described above, it is provided with a two-step transfer step of the intermediate base material 351 to the flexible base material 301 (intermediate transfer step) and the flexible base material 301 to the separator 11 (final transfer step).

(Shaping process)
The shaping step is a step of shaping the pressure-sensitive adhesive 211 to be the gasket 203 on the intermediate base material 351. The intermediate base material 351 does not have to have flexibility and may be a member made of a hard material.

As shown in FIG. 9A, the intermediate base material 351 is placed on the base 401, and the molding die 411 is placed via the intermediate base material 351. The molding die 411 is provided with a gate 412 and a cavity 413.

The intermediate base material 351 includes a protrusion 352 that enters between two adjacent beads 14B provided on one of the pair of separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). Like the bead 14B, the protrusion 352 rises from the flexible base material 301 at a rising angle of about 70 °. That is, the protrusion 352 is formed in a shape imitating the side wall 15B of the bead 14B to which the pressure-sensitive adhesive 211 serving as the gasket 203 adheres.

The cavity 413 provided in the molding die 411 has a shape for arranging the protrusion 352 provided in the intermediate base material 351 and molding the gasket 203 in the portion communicating with the gate 412.

As shown in FIG. 9B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413. As the molding method at this time, injection molding or transfer molding is adopted.

As shown in FIG. 9C, by separating the molding die 411 from the base 401, the pressure-sensitive adhesive 211 is formed on the intermediate base material 351 along the protrusion 352. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

In order to allow the adhesive 211 to be formed on the intermediate base material 351 by separating the mold 411 from the base 401, the intermediate base material 351 exhibits stronger adhesiveness than the wall portion of the cavity 413. Has been done.

(Intermediate transfer process)
The intermediate transfer step is a step of transferring the pressure-sensitive adhesive 211 formed on the intermediate base material 351 to the flexible base material 301. The flexible base material 301 has a flat shape, not the shape provided with the protrusion 302 as in the second embodiment.

As shown in FIG. 10 (A), the pressure-sensitive adhesive 211 formed on the intermediate base material 351 is made to face the flexible base material 301.

As shown in FIG. 10B, the flexible base material 301 and the intermediate base material 351 are brought close to each other, and the pressure-sensitive adhesive 211 is brought into contact with the flexible base material 301. The pressure-sensitive adhesive 211 adheres to the flexible base material 301 due to its own adhesiveness.

As shown in FIG. 10C, the flexible base material 301 is separated from the intermediate base material 351. At this time, the flexible base material 301 exhibits stronger adhesiveness than the intermediate base material 351. Therefore, the pressure-sensitive adhesive 211 maintains the state of being adhered to the flexible base material 301, and the flexible base material 301 is peeled off from the pressure-sensitive adhesive 211.

(Final transfer process)
The final transfer step is a step of transferring the pressure-sensitive adhesive 211 formed on the flexible base material 301 to the separator 11 to form the gasket 203.

As shown in FIG. 11A, the pressure-sensitive adhesive 211 formed on the flexible base material 301 is made to face the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. As shown in FIG. 4, the fixing position of the gasket 203 is the side wall 15B of the bead 14B which is nestedly overlapped with the bead 14A of the separator 11A on the side in contact with the fuel gas (hydrogen).

As shown in FIG. 11B, the separator 11B and the flexible base material 301 are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 11C, the flexible base material 301 is bent and peeled off from the adhesive 211. At this time, the separator 11B is designed to exhibit stronger adhesiveness than the flexible base material 301. Therefore, the pressure-sensitive adhesive 211 maintains the state of being adhered to the flexible base material 301, and the flexible base material 301 is peeled off from the pressure-sensitive adhesive 211.

As shown in FIG. 11D, as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

The pressure-sensitive adhesive 211 to be the gasket 203 may or may not be crosslinked, as in the first to third embodiments. Cross-linking of the pressure-sensitive adhesive 211 is carried out after shaping on the intermediate base material 351 and then transferring to the flexible base material 301 or after transferring to the separator 11B.

As a modification of the present embodiment, a region other than the bead 14B of the separator 11B or the top of the bead 14B provided on the separator 11B may be a fixed position of the gasket 203 with respect to the separator 11B. When these modifications are adopted, the pressure-sensitive adhesive 211 is shaped on the flat surface of the intermediate base material 351 in the shaping step, and the pressure-sensitive adhesive 211 is intermediate-transferred on the flat surface of the flexible base material 301 in the intermediate transfer step. ..

Thereby, in the final transfer step, the pressure-sensitive adhesive 211 can be transferred from the flexible base material 301 to the region other than the bead 14B of the separator 11B or the top of the bead 14B provided on the separator 11B.

[Fifth Embodiment]
A fifth embodiment will be described with reference to FIGS. 12 (A) to 12 (C) and FIGS. 13 (A) to 13 (D). The same parts as those in the first embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

(Shaping process)
The molding die 411 of the present embodiment includes an upper die 411U and a lower die 411L. The shaping step is a step of shaping the pressure-sensitive adhesive 211, which should be the gasket 203, into the lower mold 411L.

As shown in FIG. 12 (A), the lower mold 411L of the molding mold 411 is placed on the base 401. The upper mold 411U of the molding mold 411 is provided with a gate 412 and a cavity 413. The cavity 413 has a shape for forming the gasket 203.

As shown in FIG. 12B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413. As the molding method at this time, injection molding or transfer molding is adopted.

As shown in FIG. 12C, by separating the molding die 411 from the base 401, the adhesive 211 is formed on the flat surface of the lower die 411L. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

In order to separate the molding die 411 from the base 401 so that the adhesive 211 can be formed on the lower die 411L, the lower die 411L exhibits stronger adhesiveness than the wall portion of the cavity 413. ..

(Transfer process)
The transfer step is a step of transferring the pressure-sensitive adhesive 211 formed on the lower mold 411L to the separator 11 to form the gasket 203.

As shown in FIG. 13 (A), the pressure-sensitive adhesive 211 formed on the lower mold 411L is faced with one of the separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. In the present embodiment, a region other than the bead 14B provided on the separator 11B is set as a fixed position.

As shown in FIG. 13B, the separator 11B and the lower mold 411L are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 13C, the separator 11B is bent to peel off the adhesive 211 from the lower mold 411L. At this time, the separator 11B exhibits stronger adhesiveness than the lower mold 411L. Therefore, the pressure-sensitive adhesive 211 keeps sticking to the separator 11B and is peeled off from the lower mold 411L.

As shown in FIG. 13D, as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

The pressure-sensitive adhesive 211 to be the gasket 203 may or may not be crosslinked, as in the first to fourth embodiments. Cross-linking of the pressure-sensitive adhesive 211 is carried out after shaping into the lower mold 411L or after transferring to the separator 11B.

[Sixth Embodiment]
The sixth embodiment will be described with reference to FIGS. 14 (A) to 14 (C) and FIGS. 15 (A) to 15 (D). The same parts as those in the fifth embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

The gasket manufacturing method of the present embodiment produces a gasket 203 that conforms to the seal structure of the cooling surface seal 201 and the reaction surface seal 202 as shown in FIG. 4, similarly to the method of the second embodiment. Similar to the gasket manufacturing method of the fifth embodiment, the method of the present embodiment also includes a shaping step and a transfer step.

(Shaping process)
The shaping step is a step of shaping the pressure-sensitive adhesive 211 to be the gasket 203 on the lower mold 411L.

As shown in FIG. 14 (A), the lower mold 411L of the molding mold 411 is placed on the base 401. The upper mold 411U of the molding mold 411 is provided with a gate 412 and a cavity 413.

The lower mold 411L is provided with a protrusion 414 that enters between two adjacent beads 14B provided on one of the pair of separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). Like the bead 14B, the protrusion 414 rises from the lower mold 411L at a rising angle of about 70 °. That is, the protrusion 414 is formed in a shape imitating the side wall 15B of the bead 14B to which the pressure-sensitive adhesive 211 serving as the gasket 203 adheres.

As shown in FIG. 14B, the material 212 of the pressure-sensitive adhesive 211, for example, unvulcanized butyl rubber, which is a rubber-like elastic material, is guided from the gate 412 to the cavity 413. As the molding method at this time, injection molding or transfer molding is adopted.

As shown in FIG. 14C, by separating the molding die 411 from the base 401, the adhesive 211 is formed on the lower die 411L along the protrusion 414. The shaped pressure-sensitive adhesive 211 becomes the gasket 203.

As shown in FIG. 15 (A), the pressure-sensitive adhesive 211 formed on the lower mold 411L is faced with one of the separators 11, for example, the separator 11B on the side in contact with the oxidizing gas (oxygen). The facing position is the fixed position of the gasket 203 with respect to the separator 11B. As shown in FIG. 4, the fixing position of the gasket 203 is the side wall 15B of the bead 14B which is nestedly overlapped with the bead 14A of the separator 11A on the side in contact with the fuel gas (hydrogen).

As shown in FIG. 15B, the separator 11B and the lower mold 411L are brought close to each other, and the adhesive 211 is brought into contact with the position where the gasket 203 should be fixed. The pressure-sensitive adhesive 211 adheres to the separator 11B due to its own adhesiveness.

As shown in FIG. 15C, the separator 11B is bent to peel off the adhesive 211 from the lower mold 411L. At this time, the separator 11B exhibits stronger adhesiveness than the lower mold 411L. Therefore, the pressure-sensitive adhesive 211 keeps sticking to the separator 11B and is peeled off from the lower mold 411L.

As shown in FIG. 15D, as a result, the adhesive 211 is fixed to the separator 11B, and the adhesive 211 becomes the gasket 203.

1 Fuel cell 2

Fuel cell cell

11, 11A, 11B Separator 12 Placement area 13

Manifold

14, 14A,

14B Bead

15, 15A, 15B Side wall 101 Membrane electrode assembly 102 Electrolyte membrane (mating member)
103 Manifold 201 Cooling surface seal 202 Reaction surface seal 203 Gasket 211 Adhesive 212 Material 301 Flexible base material 302 Protrusion 351 Intermediate base material 352 Protrusion 401 Base 411 Mold

411U Upper mold

411L Lower mold 412 Cavity 413 Gate 414 Protrusion

Claims

An adhesive that serves as a gasket is formed on a flexible base material using a molding mold to form a flexible base material.
The flexible substrate is shaped with respect to one of a pair of separators having beads that face each other with the mating member in between and that form a fluid flow path between the mating member and the mating member. The adhesive is transferred to form the gasket.
A method for manufacturing gaskets for fuel cell separators.
The transfer position of the pressure-sensitive adhesive is the side surface of the bead.
The method for manufacturing a gasket for a fuel cell separator according to claim 1.
The shaping position of the pressure-sensitive adhesive is the side surface of the protrusion provided on the flexible base material that enters between the two adjacent beads.
The method for manufacturing a gasket for a fuel cell separator according to claim 2.
The protrusion of the flexible base material is molded by embossing the pressure of the pressure-sensitive adhesive on the molding die.
The method for manufacturing a gasket for a fuel cell separator according to claim 3.
Using a molding mold, a pressure-sensitive adhesive that serves as a gasket is formed on the intermediate base material.
The pressure-sensitive adhesive shaped to the intermediate base material is transferred to the flexible base material having flexibility, and the adhesive is transferred to the flexible base material.
Transferred to the flexible substrate for one of a pair of separators having beads that face each other with the mating member in between and that form a fluid flow path between the mating member and the mating member. The adhesive is transferred to form the gasket.
A method for manufacturing gaskets for fuel cell separators.
The transfer position of the pressure-sensitive adhesive is the side surface of the bead.
The method for manufacturing a gasket for a fuel cell separator according to claim 5.
The shaping position of the pressure-sensitive adhesive is the side surface of the protrusion provided on the intermediate base material.
The method for manufacturing a gasket for a fuel cell separator according to claim 6.
An adhesive serving as a gasket is formed on the lower mold of a molding mold having an upper mold and a lower mold.
It is shaped into the lower mold with respect to one of a pair of separators having beads that face each other with the mating member in between and that form a fluid flow path between the mating member and the mating member. The adhesive is transferred to form the gasket.
A method for manufacturing gaskets for fuel cell separators.
The transfer position of the pressure-sensitive adhesive is the side surface of the bead.
The method for manufacturing a gasket for a fuel cell separator according to claim 8.
The shaping position of the pressure-sensitive adhesive is the side surface of the protrusion provided on the lower mold that enters between the two adjacent beads.
The method for manufacturing a gasket for a fuel cell separator according to claim 9.